Toy aeroplane



June 10, 1958 J. BORTFELDT 2,837,864

TOY AEROPLANE Filed July 19. 1956 V 2 Sheets-Sheet 1 IN VEN TOR.

(/JZQf/V 5027/5107 BY @Qz;

June 10, 1958 J. BORTFELDT 7,

TOY AEROPLANE Filed July 19, 1956 z Sheets-Sheet 2 3! INVENTOR.

Ju'kas/v Baler/40 r Sta es Patent 2,831,864 TOY AEROPLANE' JiirgenBortfeldt, Lehrte, Hannover, Germany, assignor to K. Arnold & Co.,Numberg, Germany Application July 19, 1956, Serial No. 598,777 Claimspriority, application Germany December 23, 1952 2 Claims. (CI. 46-77)The present invention relates to toys and, more specifically, concerns acaptive toy aeroplane which has associatedtherewith a device to be heldby the hand of theplaying childand a flexible-shaft interconnecting saiddevice and the toy aeroplane, while said device is.

operable to convey driving forces through said flexible shaft .to saidpropeller.

.This' application is a continuation-in-part application of my.co-pending application Serial Number-398,170 filed December 14, 1953,now'abandoned.

A toy airplane of this type is known. in which the flexible shaft isintroduced into the fuselage from below the invention, the flexibledrive shaft consists of a twist resistant wire or the like. A driveshaft of a pulled-out helical spring has proved particularlyadvantageous in this connection. shaft preferably consists of hard steelwire.

Tests have proved that with the design of the drive shaft according tothe present invention, the drive shaft may have a length up to'and morethan 21 yards. In view of its low weight, the wire is carried by theaeroplane without any ditficulties.

In order to convey the necessary driving power through the transmissionshaft to the propeller and thereby the toy aeroplane, a strong torque isrequired which, however, has the undesired effect that the driving wireor flexible driving shaft will tend to form loops. This is particularlythe case when the toy aeroplane is to be started because in such aninstance there are no centrifugal or air forces present which can actupon the toy aeroplane in the direction of the flexible drive shaft.

'Applicant has realized that in order to design a remotely driven toyaeroplane which may be airborne it is necessary from the very start toproduce a considerable air force which will hold the flexible shaft instretched out condition. To this end, the intermediate transmissionshaft between the propeller shaft and the flexible power conveying shaftis arranged in such a manner that said "portion of the plane.

provide a captive toy aeroplane which will overcome the above mentioneddrawbacks.

It is another object of this inventionto provide a captive toyaeroplane. which is characterized by a great flying stability.

Still another object of this invention consists in the provision ofa toyaeroplane which will avoidaccidental twisting of the drive shaft leadingto said aeroplane.

A still further object of this invention consists in the provision of'atoy aeroplane which will be adapted'to,

start from the ground.

These and other objects and advantages of the invention will appear moreclearly from the following specificafiion inconnection with theaccompanying drawings in w ich: 1

Fig. 1 illustrates a top view of a toy aeroplane accord-.-

ing to the invention with direct drive of the propeller by a flexibledrive shaft. Y Fig, 2 is a side view of the toy shown in Fig. 1.- Fig. 3is a partialsection through a manually operable driving device for a toyaeroplane according to the in-- vention. v I

Fig. 4 illustrates a top view of a further embodiment of a toy aeroplaneaccording to the invention w hich is shaft and the propeller.

Fig. 5 is a side view of Fig. 4.

provided with a step down transmission between the drive Generalarrangement or is passed to the aeroplane approximately at the end of awing. According to a further important feature of intermediate shaftforms an acute angle with the transverse axis of the aeroplane, orexpressed in a different manner, the said intermediate shaft forms withthe longitudinal axis of said plane an obtuse angle toward the front Inthis way the propeller exerts not only a forward drive but also exerts astrong pull upon the drive shaft so that the toy aeroplane can startwithout forming loops.

While it is also possible by adjustment of the side rudder or by settingthe propeller shaft at an angle to obtain an additional outwardlydirected air force, these last mentioned two steps are not as favorableas the inclination of the intermediate shaft between the propeller shaft7 and the flexible drive shaft.

Due to the fact that the drive shaft is arranged on one side of thefuselage, especially at the end of a wing, a torque is exerted upon theplane which has the tendency to turn the plane by a certain angle aboutits longitudinal axis. In order to avoid that due to the said torque theplanewill assume a right or left wing low attitude, the plane may beprovided with means which will either partly or entirely counteract orcompensate said torque.

The danger of twisting of the drive shaft can be further decreased bymaintaining the torque to be conveyed of the propeller. If the propellerand the drive shaft are driven at the same speed of rotation, the mostsimple arrangement consists in connecting the propeller directly withthe drive shaft without intermediate transmission. If, however, thespeed of rotation of the drive shaft is to be higher than that ofthepropeller, a corresponding transmission is provided which may bearranged in the,

hollow fuselage. For driving the'flexible shaft, there may accordiug toan extremely simple solution; bepros 7 vided'atransmission' arranged ina casing and provided with a crank. In this instance it has provedparticularly advantageous to select the transmission approximately Thedrive wire making up said drive Structural arrangement Referring now tothe drawings in detail, and more particularly, to Figs. l and 2, the toyaeroplane illustrated therein may consist of a light but neverthelessresistant material such as wood or any other appropriate material. Themodel plane consists primarily of a fuselage I having connected theretothe wings 2 and 3 as well as the tail plane 4. the elevator 5, the tailfin 6 and the side rudder '7. The elevator 5, side rudder 7 and also thefins 4- and 6 may consist of a flexible material as for instance sheetmetal, so that their position canbe adjusted. Below the wings 2 and 3,there are the two wheels 8 and19 with respective struts, making up thelanding gear. Below the tail unit there is a resilient tail skid 10. Thepropeller 11 is arranged atthe nose of the fuselage 1. The propellershaft 12 is easily rotatably journalled in the fuselage 1 and isdirected outwardly by an angle of approximately 10 degrees. Thepropeller shaft 12 is connected with a shaft 14 through the interventionof a flexible shaft portion 13 which consists of a spiral spring. Theshaft 14 is easily rotatably journalled at the leading edge of the righthand wing 3' by means of the bearing 15. The shaft 14 has an angle ofinclination of approximately degrees with regard to the transverse axisof the toy aeroplane. Howeventhis angle ofinclination is not limited toapproximately 5 degrees but may effectively vary from 3 to degrees. Oneend of the drive shaft. 16 is drivingly connected with the shaft 14,while the other end of said drive shaft 16 is drivingly connected with adriving mechanism which will. be explained later. It should. be notedthat the side rudder is greatly turned outwardly.

. Referring now to the driving mechanism illustrated in Fig. 3, thismechanism consists primarily of acasing. 17, housing atransmission. Inthe transmission frame 18 there. is journall'ed a strong crank 19, therotational move ments of which are conveyed. through. gears 20, 21, 22and 23 to a crown wheel 24 and from the latter to a. driving pinion 25.'The shaft 26 of the drive pinion 25 is connected with the flexible driveshaft 16.

Operation The operation of the toy aeroplane according to the inventionis extremely simple as will presently appear. The toy plane is placed ona fairly even surface while care is taken that the flexible shaft 16 isheld straight between the toy plane and the driving device held by thehand of the playing child. If now the crank 19 is rotated, a strongrotational movement is conveyed to the propeller through theintervention of the flexible shaft 16 so that the toy plane startsmoving and after a short take-off roll, becomes airborne; Due to theinclined position of the shaft 14, the propeller and the side rudder, anaerodynamic force is produced which holds the flexible drive' shaft instretched-out position. The maximum altitude of the model plane dependson the length of the flexible drive shaft, which may amount to 21 yardsand more. speed of rotation of the propeller. With increasing speed ofthe crank, the toy plane flies and with decreasing'spee'd of the crankthe toy plane descends.

. If the playing child remains at one and the same spot, the model planedescribes acircular path asia' result of which the occurringcentrifugal'force will aid the outwardly directed aerodynamic force in its tendencyto maintain the drive shaft16 in stretched-out position. It

is, of course, also possible to drive the toy plane from a moving'point,as, for instance, from a vehicle, in which The respective altitude canbe adjusted by the.

instance the plane will perform a straight line of flight or will fiyany desired pattern, depending upon the movement of the moving point. Bycausing the driving mechanism gradually to reduce its speed to zero, theplane can he landed in a natural manner. When reversing the direction ofrotation of the drive shaft, also a braking effect can be producedduring the landing operation.

The embodiment illustrated in Fig. 4 shows a toy aeroplane composed ofhollow bodies, for instance of half shells 'of thin material. The planemodel shown in Fig. 4

consists of the hollow fuselage 27 having connected thereto the likewisehollow Wings 28, 29, the elevator assembly 30, 31 and the rudderassembly 32, 33. The side rudder '33 is also in this instance stronglyturned toward the out side. Below the wings 28, 29 there are the wheels34, 35 with the respective struts which together make up the landinggear.

The propeller 36 is arranged at the nose of the fuselage 27. Accordingto the arrangement shown in Fig. 4, the

propeller shaft 37 extends in the direction of the longitudinal axis ofthe toy aeroplane andis journalled in two.

transverse Walls 38 and 39 within the fuselage 27. The rear end of thepropeller shaft 37 is provided with a crown wheel 40. Furthermore, inthe wing 29,- there is provided a shaft 41 which is journalled near theleading edge of the wing 29 by means of bearing blocks 42 and isjou'rnalled in the fuselage 27 in the wall portion 43. As has beenclearly shown in Fig. 4', also in this instance the shaft 41 i isinclined to the transverse axis of the aeroplane by about 8 degreesalthough this angle of inclination may vary similar to theangle ofinclination referred to in connection with the intermediate shaft 14 ofFig. 1. That end of the shaft 41 which extends into the fuselage isprovided with the pinion 44 which meshes with the crown wheel 40. Theother end of shaft 41 protrudes somewhat from the tip of the wing 29 andis connected with the flexible drive shaft 45. The flexible drive shaft45 is in the form of a coiled steel wire with the'windings pulled apartsomewhat. In some exceptional instances the Wing 28 may at its tip beprovided with a counter weight 46. However, it has been found in actualpractice that generally the counter weight 46 is not necessary. Thedriving mechanism for the toy'aeroplane of Fig. 4 may for instance bedesigned similar to the driving mechanism shown in Fig. 3.

It is t'o be understood that the present invention is, by no means,limitedto the specific constructions shown in thedra'win'g'sbut alsocomprises any modifications within the scope of the appended claims.

Wliat I claim" is:

1 A captive toy' airplane, which comprises in combination: a fuselage,two wings supported by'said fuselage, a propeller shaft journalled inthe front portion of said fus'elage, a propeller connected to one end ofsaid propeller shaft, an intermediate shaft rotatably supported by oneof said wings and located substantially in the plane passing ing deviceand: having" its other end drivingly connected with the other end ofsaid intermediateshaft.

2. A captive toy airplane according to claim- 1, in which theintermediateshaft defines with said propeller shaft an angle of at leastnearly 5.

References Gited in the file ofthis patent UNITED STATES PATENTS2,611,213 Johnson et al Sept. 23, 1952 2,756,537 Ernst July 31, 1956FGREIGN- PATENTS Great Britain May 30, 1956

